ON STRUCTURED AND DIFFUSE SEISMICITY, STIFFNESS OF EARTHQUAKE FOCI, AND NONLINEARITY OF MAGNITUDE RECURRENCE GRAPHS

Geological, geophysical and seismogeological studies are now conducted in a more detail and thus provide for determining seismic sources with higher accuracy, from the first meters to first dozens of meters [Waldhauser, Schaff, 2008]. It is now possible to consider uncertainty ellipses of earthquake...

Full description

Saved in:
Bibliographic Details
Main Author: Evgeny G. Bugaev
Format: Article
Language:English
Published: Russian Academy of Sciences, Siberian Branch, Institute of the Earth's crust 2015-09-01
Series:Геодинамика и тектонофизика
Subjects:
Online Access:https://www.gt-crust.ru/jour/article/view/135
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849242689032159232
author Evgeny G. Bugaev
author_facet Evgeny G. Bugaev
author_sort Evgeny G. Bugaev
collection DOAJ
description Geological, geophysical and seismogeological studies are now conducted in a more detail and thus provide for determining seismic sources with higher accuracy, from the first meters to first dozens of meters [Waldhauser, Schaff, 2008]. It is now possible to consider uncertainty ellipses of earthquake hypocenters, that are recorded in the updated Earthquake Catalogue, as surfaces of earthquake focus generators. In our article, it is accepted that a maximum horizontal size of an uncertainty ellipse corresponds to an area of a focus generator, and seismic events are thus classified into two groups, earthquakes with nonstiff and stiff foci. Criteria of such a classification are two limits of elastic strain and brittle strain in case of uniaxial (3⋅10–5) or omnidirectional (10–6) compression. The criteria are established from results of analyses of parameters of seismic dislocations and earthquake foci with regard to studies of surface parameters and deformation parameters of fault zones. It is recommendable that the uniaxial compression criterion shall be applied to zones of interaction between tectonic plates, and the unilateral compression criterion shall be applied to low active (interplate) areas. Sample cases demonstrate the use of data sets on nonstiff and stiff foci for separate evaluation of magnitude reoccurrence curves, analyses of structured and dissipated seismicity, review of the physical nature of nonlinearity of recurrence curves and conditions of preparation of strong earthquakes. Changes of parameters of the recurrence curves with changes of data collection square areas are considered. Reviewed are changes of parameters of the recurrence curves during preparation for the Japan major earthquake of 11 March 2011 prior to and after the major shock. It is emphasized that it is important to conduct even more detailed geological and geophysical studies and to improve precision and sensitivity of local seismological monitoring networks in zones of nuclear stations and other hazardous facilities. It is noted that a list of parameters recorded in earthquake catalogues needs to be extended. Based on the above, it will be possible to ensure proper monitoring of stability of the seismic process during construction, operations and decommissioning of nuclear stations.
format Article
id doaj-art-b69a7c5ba15644268bebf2f870378e2d
institution Kabale University
issn 2078-502X
language English
publishDate 2015-09-01
publisher Russian Academy of Sciences, Siberian Branch, Institute of the Earth's crust
record_format Article
series Геодинамика и тектонофизика
spelling doaj-art-b69a7c5ba15644268bebf2f870378e2d2025-08-20T03:59:45ZengRussian Academy of Sciences, Siberian Branch, Institute of the Earth's crustГеодинамика и тектонофизика2078-502X2015-09-012324426510.5800/GT-2011-2-3-0045134ON STRUCTURED AND DIFFUSE SEISMICITY, STIFFNESS OF EARTHQUAKE FOCI, AND NONLINEARITY OF MAGNITUDE RECURRENCE GRAPHSEvgeny G. Bugaev0Scientific and Engineering Centre for Nuclear and Radiation Safety, Federal AgencyGeological, geophysical and seismogeological studies are now conducted in a more detail and thus provide for determining seismic sources with higher accuracy, from the first meters to first dozens of meters [Waldhauser, Schaff, 2008]. It is now possible to consider uncertainty ellipses of earthquake hypocenters, that are recorded in the updated Earthquake Catalogue, as surfaces of earthquake focus generators. In our article, it is accepted that a maximum horizontal size of an uncertainty ellipse corresponds to an area of a focus generator, and seismic events are thus classified into two groups, earthquakes with nonstiff and stiff foci. Criteria of such a classification are two limits of elastic strain and brittle strain in case of uniaxial (3⋅10–5) or omnidirectional (10–6) compression. The criteria are established from results of analyses of parameters of seismic dislocations and earthquake foci with regard to studies of surface parameters and deformation parameters of fault zones. It is recommendable that the uniaxial compression criterion shall be applied to zones of interaction between tectonic plates, and the unilateral compression criterion shall be applied to low active (interplate) areas. Sample cases demonstrate the use of data sets on nonstiff and stiff foci for separate evaluation of magnitude reoccurrence curves, analyses of structured and dissipated seismicity, review of the physical nature of nonlinearity of recurrence curves and conditions of preparation of strong earthquakes. Changes of parameters of the recurrence curves with changes of data collection square areas are considered. Reviewed are changes of parameters of the recurrence curves during preparation for the Japan major earthquake of 11 March 2011 prior to and after the major shock. It is emphasized that it is important to conduct even more detailed geological and geophysical studies and to improve precision and sensitivity of local seismological monitoring networks in zones of nuclear stations and other hazardous facilities. It is noted that a list of parameters recorded in earthquake catalogues needs to be extended. Based on the above, it will be possible to ensure proper monitoring of stability of the seismic process during construction, operations and decommissioning of nuclear stations.https://www.gt-crust.ru/jour/article/view/135ellipse of uncertainty; the earthquake source: rigidslowstructureddiffuse; recurrence curve magnitudes: linear and nonlinear
spellingShingle Evgeny G. Bugaev
ON STRUCTURED AND DIFFUSE SEISMICITY, STIFFNESS OF EARTHQUAKE FOCI, AND NONLINEARITY OF MAGNITUDE RECURRENCE GRAPHS
Геодинамика и тектонофизика
ellipse of uncertainty; the earthquake source: rigid
slow
structured
diffuse; recurrence curve magnitudes: linear and nonlinear
title ON STRUCTURED AND DIFFUSE SEISMICITY, STIFFNESS OF EARTHQUAKE FOCI, AND NONLINEARITY OF MAGNITUDE RECURRENCE GRAPHS
title_full ON STRUCTURED AND DIFFUSE SEISMICITY, STIFFNESS OF EARTHQUAKE FOCI, AND NONLINEARITY OF MAGNITUDE RECURRENCE GRAPHS
title_fullStr ON STRUCTURED AND DIFFUSE SEISMICITY, STIFFNESS OF EARTHQUAKE FOCI, AND NONLINEARITY OF MAGNITUDE RECURRENCE GRAPHS
title_full_unstemmed ON STRUCTURED AND DIFFUSE SEISMICITY, STIFFNESS OF EARTHQUAKE FOCI, AND NONLINEARITY OF MAGNITUDE RECURRENCE GRAPHS
title_short ON STRUCTURED AND DIFFUSE SEISMICITY, STIFFNESS OF EARTHQUAKE FOCI, AND NONLINEARITY OF MAGNITUDE RECURRENCE GRAPHS
title_sort on structured and diffuse seismicity stiffness of earthquake foci and nonlinearity of magnitude recurrence graphs
topic ellipse of uncertainty; the earthquake source: rigid
slow
structured
diffuse; recurrence curve magnitudes: linear and nonlinear
url https://www.gt-crust.ru/jour/article/view/135
work_keys_str_mv AT evgenygbugaev onstructuredanddiffuseseismicitystiffnessofearthquakefociandnonlinearityofmagnituderecurrencegraphs